Lift and pivot device for a cover of a furnace and furnace system and method for charging and servicing such a furnace system

Abstract

A lift and pivot device for a cover of a furnace including a guide housing having a base plate, a rotatably mounted slide roller, and a vertical opening; a lift pin that can be lifted and lowered inside the vertical opening; a lift cylinder for lifting and lowering the lift pin, the lift cylinder being articulated to the lift pin at one end as well as articulated and rotatably connected to the base plate at the other end; and a guide frame for carrying the cover. The guide frame includes a support arm, wherein an upper end of the support arm is equipped for connection to the cover and includes a lift nose having a lift eye which is in engagement with an end of the lift pin facing away from the lift cylinder. The support arm at the other end thereof has a slide plate.

The invention claimed is: 
     
       1. A lift and pivot device comprising
 a guide housing having a base plate, a rotatably mounted slide roller and a vertical opening, 
 a lift pin which can be lifted and lowered inside the vertical opening in the guide housing, 
 a lift cylinder to lift and lower the lift pin, the lift cylinder being connected at one end in articulated fashion to the lift pin and at another end in articulated fashion and rotatably to the base plate, and 
 a guide frame to carry a cover of a furnace, the guide frame including a support arm having a first end and a second end, the first end being an upper end of the support arm and being equipped for connection to the cover, the first end including a lift nose having a lift eye which can be engaged with an end of the lift pin facing away from the lift cylinder; and 
 a slide plate at the second end of the support arm, 
 wherein a lateral face of the slide roller rolls on the slide plate during the lifting and lowering of the lift cylinder, 
 wherein the slide roller connects the guide housing to the guide frame such that movement of the guide frame with respect to the guide housing is via the slide roller. 
 
     
     
       2. The lift and pivot device as claimed in  claim 1 , wherein the slide roller is connected to an automatic lubricant supply system. 
     
     
       3. The lift and pivot device as claimed in  claim 1 , further comprising:
 a sealing device of variable length fastened at one end on the guide housing and at another end on an end of the lift pin facing the lift nose, the sealing device radially surrounding a part of the lift pin raised in a direction of the lift nose from the guide frame during the lifting and lowering of the lift cylinder. 
 
     
     
       4. The lift and pivot device as claimed in  claim 3 , wherein the sealing device of variable length is formed by a tubular bellows seal. 
     
     
       5. The lift and pivot device as claimed in  claim 1 , wherein the slide roller is rotatable around a slide roller axis of rotation, the position of the slide roller axis of rotation being adjustable with respect to the guide housing. 
     
     
       6. The lift and pivot device as claimed in  claim 1 , wherein the end of the lift pin facing away from the lift cylinder is conically tapered or hemispherically tapered. 
     
     
       7. The lift and pivot device as claimed in  claim 1 , wherein
 the slide roller is a first slide roller and the slide plate is a first slide plate, 
 the guide housing has a rotatably mounted second slide roller, 
 the lift and pivot device further comprises a second slide plate at the second end of the support arm, and 
 a lateral face of the second slide roller rolls on the second slide plate during the lifting and lowering of the lift cylinder. 
 
     
     
       8. The lift and pivot device as claimed in  claim 7 , wherein:
 the first and second slide rollers are rotatable around first and second slide roller axes of rotation, respectively, 
 the first and second slide roller axes of rotation lie in a horizontal plane and are oriented in a V-shape with respect to one another, wherein a tip of the V, which corresponds to a virtual point of intersection of the first and second slide roller axes of rotation, points away from the guide frame. 
 
     
     
       9. The lift and pivot device as claimed in  claim 1 , further comprising:
 a centering device to position the guide frame with respect to the guide housing when the lift pin has been lifted. 
 
     
     
       10. The lift and pivot device as claimed in  claim 1 , further comprising:
 at least one electrode carrying arm, which is liftable and pivotable with respect to the guide housing, being connected to the guide housing. 
 
     
     
       11. A furnace system comprising:
 the lift and pivot device as claimed in  claim 1 ; 
 a furnace having a furnace vessel; and 
 the cover, 
 wherein the lift and pivot device is connected to the cover, the cover is fastened on an upper end of the guide frame with respect to the lift nose on the support arm and the guide housing is arranged pivotably around a vertical axis of rotation with respect to the furnace vessel. 
 
     
     
       12. A method for use with the furnace system as claimed in  claim 11 , the method comprising:
 lifting the lift pin via the lift cylinder, wherein the end of the lift pin facing away from the lift cylinder engages with the lift eye, the guide frame together with cover is lifted and the slide plate is moved upward on the slide roller; 
 pivoting the guide housing including the guide frame and the cover around a vertical axis of rotation from an operating position in which the furnace vessel is closed by the cover into a charging position in which the cover uncovers the furnace vessel; 
 charging the furnace vessel with charge material to be melted; 
 pivoting the guide housing including the guide frame and the cover around the vertical axis of rotation from the charging position back into the operating position; and 
 lowering the lift pin via the lift cylinder, wherein the guide frame together with cover is lowered and the slide plate is moved downward on the slide roller. 
 
     
     
       13. The method as claimed in  claim 12 , comprising:
 lowering the lift pin via the lift cylinder in an operating position in which the furnace vessel is closed by the cover, wherein the end of the lift pin facing away from the lift cylinder slides out of the lift eye and the slide plate is moved downward on the slide roller; 
 pivoting the guide housing around a vertical axis of rotation from an operating position into a servicing position, wherein the cover remains on the furnace vessel, 
 servicing the lift and pivot device ( 1 ) or another part of the furnace system, and 
 pivoting the guide housing around the vertical axis of rotation from the servicing position back into the operating position. 
 
     
     
       14. The method as claimed in  claim 13 , wherein
 the lift and pivot device further comprises at least one electrode carrying arm, which is liftable and pivotable with respect to the guide housing, connected to the guide housing, 
 the method further comprising:
 prior to the pivoting of the guide frame around the vertical axis of rotation from the operating position into the charging position or servicing position, lifting the at least one electrode carrying arm with respect to the guide housing and the cover, and 
 after the pivoting of the guide housing around the vertical axis of rotation from the charging position or servicing position back into the operating position, lowering the at least one electrode carrying arm with respect to the guide housing and the cover. 
 
 
     
     
       15. The lift and pivot device as claimed in  claim 1 , wherein the furnace is an electric arc furnace. 
     
     
       16. The lift and pivot device as claimed in  claim 5 , wherein the furnace is an electric arc furnace. 
     
     
       17. The lift and pivot device as claimed in  claim 8 , wherein the furnace is an electric arc furnace. 
     
     
       18. The lift and pivot device as claimed in  claim 10 , wherein the furnace is an electric arc furnace. 
     
     
       19. The furnace system as claimed in  claim 11 , wherein the furnace is an electric arc furnace. 
     
     
       20. The method as claimed in  claim 12 , wherein the furnace is an electric arc furnace.